This invention relates to pinking shears of the type having integral flanges projecting transversely from the insides of the blades along their leading edges and in which flanges the pinking teeth are formed so that the shearing edges of the teeth of one blade mesh with and pass through the shearing edges of the teeth of the other blade as the blades are closed.
In prior art shears of this character, various proposals have been made for ensuring that the blades properly coact with one another throughout the length of their cutting stroke, and this is usually accomplished by providing coacting raised portions at the handle side of the pivot. For example, the German Patent 592897 of Feb. 17, 1934 provides opposed, bevelled edges to ensure the proper cutting action. However, it does not provide for precise meshing of the teeth during their initial engagement and a spring around the pivot post provides the pressure between the opposed teeth. The German Pat. No. 610297 of Mar. 7, 1935 utilizes a flat leaf spring to provide cutting pressure between the opposed teeth but no provision is made for ensuring proper mesh of the teeth particularly during the initial engagement of the teeth.
U.S. Pat. No. 2,578,616 of Dec. 11, 1951 uses a resilient body such as a rubber type pad to provide the cutting force between the teeth. There is no provision for ensuring precise alignment of the teeth themselves, particularly during the initial cutting action.